Unit for dispensing a fluid product and device for distributing a fluid product comprising such a unit

ABSTRACT

A fluid dispenser member having a body and manually-actuated dispenser mechanism movable in the body between rest and dispensing positions. The dispenser mechanism urged by a resilient member towards the rest position by a plurality of spring cells arranged in parallel around a longitudinal axis of the resilient member, forming a spring stage. The resilient member includes a plurality of spring stages that are superposed along the longitudinal axis. A spring stage has a top undulating ring having multiple undulations, and a bottom undulating ring having multiple undulations, the top and bottom undulations arranged relative to each other so that the top and bottom undulating rings are in contact at a plurality of contact points distributed around the longitudinal axis. A spring cell is defined between two adjacent contact points of the spring stage, the resilient member is made of a synthetic material.

The present invention relates to a fluid dispenser member and to a fluid dispenser device including such a dispenser member.

Fluid dispenser members are well known, in particular for dispensing, in selective manner, fluids such as liquids or powders, in particular in the fields of pharmacy, perfumery, and cosmetics. By way of example, such fluid dispenser members may be pumps, valves, or air expellers. They are generally associated with a reservoir containing the fluid, so as to form a fluid dispenser device. In conventional manner, a fluid dispenser member comprises a body and dispenser means that are moved in said body manually by the user between a rest position and a dispensing position, said movement making it possible to dispense the fluid. A resilient member, such as a spring, is generally used to urge said dispenser means towards their rest position, so that the user must exert a force in order to achieve the movement towards the dispensing position, and when the user relaxes the force, said resilient member automatically returns the dispenser means into their rest position. Generally, spiral springs made of metal are used as return springs. This may present a certain number of drawbacks. Thus, the metal may interact with the fluid, in particular when it is a pharmaceutical, and this may have a harmful effect on said fluid to be dispensed. In addition, the resilient properties of spiral springs are not always good enough, making it necessary to have springs of a size that is large in order to guarantee safe and reliable operation of the dispenser member. However, in certain applications, it may be desirable to reduce the size of said resilient member. In addition, spiral springs that are constituted by a plurality of turns in series one after another, do not present satisfactory prevention of creep under stress. In addition, a metal spring is generally made by deforming a continuous strip or coil in such a manner that the end portions of the springs are never completely flat, thus causing elastic deformation stresses to be axially distributed in non-uniform manner. In addition, a malfunctioning of one of the turns in the series may cause the spring to lose significant performance, which may also be a drawback, in particular in devices for dispensing a large number of doses, and therefore intended to be actuated a large number of times. Documents EP 1 477 234 and EP 1 565 270 describe springs made of plastics materials, the springs comprising deformable rings that are connected together via rigid axial bridges of material. During elastic deformation, a wide variety of stresses are thus created, with some portions that are greatly stressed in the deformed ring portions, and other portions that are stressed little in the rigid bridges. Thus, the resilience of this type of spring is not guaranteed to last over time. In addition, the deformation capacity of this type of spring is not as good as it might be, because of the bridges of rigid material.

An object of the present invention is to provide a fluid dispenser member and a fluid dispenser device including such a member that do not reproduce the above-mentioned drawbacks.

In particular, an object of the present invention is to provide a fluid dispenser member that reduces, or even eliminates, the risks of harmful interaction between the fluid and the parts making up said dispenser member.

Another object of the present invention is to provide such a fluid dispenser member that makes it possible to achieve optimal resilient properties with maximum compactness.

Another object of the present invention is to provide such a fluid dispenser member that presents improved properties for preventing creep under stress.

Another object of the present invention is to provide such a fluid dispenser member that can accommodate large-amplitude adjustment of load and deformation depending on the type of device in which it is used.

Another object of the present invention is to provide such a fluid dispenser member that is simple and inexpensive to manufacture and to assemble and that is safe and reliable in use.

The present invention thus provides a fluid dispenser member comprising a body and manually-actuated dispenser means that are movable in said body between a rest position and a dispensing position, said dispenser means being urged resiliently towards their rest position by a resilient member, said resilient member comprising a plurality of spring cells that are arranged in parallel around a longitudinal axis of said resilient member, forming a spring stage, and said resilient member includes a plurality of spring stages that are superposed along said longitudinal axis, a spring stage comprising a top undulating ring having multiple undulations, and a bottom undulating ring having multiple undulations, said top and bottom undulations being arranged relative to each other in such a manner that said top and bottom undulating rings are in contact at a plurality of contact points distributed around said longitudinal axis, a spring cell being defined between two adjacent contact points of said spring stage, said resilient member being made of a synthetic material, such as polyoxymethylene (POM), in particular by injection molding.

Advantageously, the top undulating ring of a spring stage forms the bottom undulating ring of the spring stage arranged directly above, and the bottom undulating ring of said spring stage forms the top undulating ring of the spring stage arranged directly below.

Advantageously, the contact points of a spring stage are offset relative to the contact points of the spring stages that are directly above and directly below, a contact point of the spring stage being arranged half way between two contact points of the spring stage that is directly above, and half way between two contact points of the spring stage that is directly below.

Advantageously, the top and bottom axial ends of said resilient member are formed by flat rings.

Advantageously, said synthetic material is filled with materials that increase resilience and/or prevent creep, such as glass fibers and/or carbon nanotubes.

Advantageously, said fluid is a liquid or powder medication.

Advantageously, said dispenser member is a pump or a valve, said dispenser means being the pump piston or the valve member, and said resilient member forming the return spring of said pump or valve.

Advantageously, said dispenser member is a compressed-air expeller, said dispenser means being the piston of the air expeller, and said resilient member forming the return spring of said air expeller.

The present invention also provides a fluid dispenser device comprising a reservoir containing said fluid, and further comprising a dispenser member as described above.

These characteristics and advantages and others of the present invention appear more clearly from the following detailed description thereof, given by way of non-limiting example, and with reference to the accompanying drawing, in which:

FIG. 1 is a diagrammatic section view of a portion of a fluid dispenser member in a first variant embodiment of the present invention;

FIG. 2 is a view similar to the view in FIG. 1, showing another variant embodiment of a fluid dispenser member of the present invention; and

FIG. 3 is a diagrammatic perspective view of a detail of a resilient member, in an advantageous embodiment of the present invention.

FIG. 1 shows a first variant embodiment of a fluid dispenser member 10 of the present invention. In this first variant embodiment, the fluid dispenser member 10 is a pump that includes a pump body 11 in which there slides a piston 20 forming manually-actuated dispenser means. When the piston 20 is moved in said body 11 towards its dispensing position, it expels a dose of fluid through a dispenser orifice 12 of the pump, said dispenser orifice generally being connected to a dispenser head (not shown) that includes a spray orifice through which the fluid is actually dispensed to the user. The piston 20 is urged by a resilient member 100 towards its rest position, and when the user manually actuates the pump, the piston 20 is driven inside the pump body 11, compressing the resilient member 100. When the user relaxes the actuation force, said compressed resilient member 100 automatically returns the piston 20 of the pump 10 into its rest position, which is the position shown in FIG. 1. The pump shown in FIG. 1 is a pump of a particular type, and naturally the present invention is not limited to this particular pump, but may relate to any type of pump. It should also be observed that a valve could also be used as fluid dispenser member of the present invention. In such a configuration, it is not a piston but a valve member that moves inside an appropriate valve body, against the force of the resilient member.

FIG. 2 shows another variant embodiment of a fluid dispenser member 10 of the present invention. In this second variant, the fluid dispenser member 10 is an air expeller including a body 11 in which a piston 20 moves so as to compress the air and thus create a compressed-air expeller. The compressed air makes it possible to dispense a dose of fluid, generally of powder, arranged downstream from said air expeller. When the user presses on the air-expeller piston 20, the resilient member 100 and the air contained inside the air-expeller body 11 are compressed until the compressed air is dispensed, e.g. when a given compression threshold is reached or when an appropriate orifice 12 opens mechanically. Then, when the user relaxes the actuation force on the air-expeller piston 20, and said air-expeller piston is returned automatically towards its rest position by the compressed resilient member 100. The user may then change the fluid cartridge, or the like, of the fluid dispenser device with which said air expeller is associated, so as to dispense the next dose. Once again, FIG. 2 only shows one particular embodiment, and obviously the present invention is not limited by the variant shown.

In the invention, the resilient member 100 presents a particular structure that is very different from a spiral spring normally used in this type of device. FIG. 3 is a diagrammatic perspective view showing an advantageous embodiment of the resilient member 100. The resilient member comprises a plurality of spring cells C that are arranged in parallel around the longitudinal axis X of the resilient member 100. The plurality of parallel spring cells C form a spring stage N. In the invention, the resilient member 100 includes a plurality of spring stages N−2, N−1, N, N+1, N+2 and N+3 in FIG. 3. Naturally, some other number of spring stages may be used. The spring stages are superposed one on another along said longitudinal axis X.

With reference more particularly to the spring stage N, said spring stage comprises a top undulating ring 110 having multiple undulations, and a bottom undulating ring 120 also having multiple undulations. The top and bottom undulating rings 110, 120 are arranged in such a manner that they touch at a plurality of contact points P distributed around said longitudinal axis X. Thus, a trough of the top undulating ring comes into contact with a crest of the bottom undulating ring so as to form a contact point P. In this way, a spring cell C is formed between two adjacent contact points P, and a plurality of spring cells C are thus distributed around the periphery of the spring stage N.

As can be seen in FIG. 3, the top undulating ring of the spring stage N forms the bottom undulating ring of the spring stage N+1 arranged directly above, and the bottom undulating ring of the spring stage N forms the top undulating ring of the spring stage N−1 arranged directly below. In other words, each spring stage has the same number of spring cells C and contact points P. In particular, the contact points of the spring stage N are offset relative to the contact points of the spring stages N+1, N−1 that are directly above and directly below, with a contact point of the spring stage N that is arranged half way between two contact points of the spring stage N+1 that is directly above, and half way between two contact points of the spring stage N−1 that is directly below. In other words, the contact points of one spring stage form the crests of the spring cells of the spring stages that are directly above and below, and vice versa.

Preferably, the top and bottom axial ends of the resilient member 100 are formed by completely flat rings 130, 140. Thus, the first spring stages starting from the top and from the bottom of the resilient member 100 are not complete spring stages since their spring cells C are not formed by two undulating rings but by only one undulating ring associated with a flat ring. In the embodiment in FIG. 3, the resilient member 100 comprises six complete spring stages, plus two partial levels defined by the top and bottom axial ends 130, 140.

This structure having a plurality of levels of multiple cells in parallel is particularly advantageous. Firstly, it enables resilient members to be made that are compact. Compared to a conventional spiral spring, the same compression force can be obtained by the resilient member of the present invention for a size occupying about 50% of the axial space. The resilient member of the present invention is thus particularly suited to short deformation strokes, e.g. up to about 20 millimeters (mm) of deformation, that are characteristic of pumps or valves used in the pharmaceutical industry. In addition, the resilient member 100 of the present invention presents improved characteristics for preventing creep under stress, since it is made up of several series of cells that are arranged in parallel, unlike spiral springs that are constituted by cells or turns that are arranged only in series. In addition, the elastic deformation is distributed in substantially homogeneous or uniform manner over all of each cell, and this favors the life span of the spring and the consistency of its performance over time, eliminating any localized zones that are greatly stressed on each actuation. This is further reinforced by the completely flat top and bottom rings that distribute the axial deformation force over all of the cells of the spring in homogeneous manner. In addition, as a function of the thickness of the rings, of their round or rectangular or other section, of their material, and of the size of the spring cells, it is possible to perform large-amplitude adjustment of load and deformation depending on the type of dispenser device in which the resilient member is used. The present invention thus applies very particularly to fluid dispenser devices for the pharmaceutical field, and in particular for dispensing liquid or powder medication by means of pumps, valves, powder inhalers, single-dose inhalers, etc.

Preferably, the resilient member 100 is made of synthetic material, in particular by injection-molding or by molding. This serves in particular to avoid the risks of harmful interaction between the resilient member and the fluid to be dispensed. For example, the resilient member 100 may be made of POM. Other materials may also be envisaged. Advantageously, the synthetic material may be filled with one or more materials that increase resilience and/or prevent creep, such as glass fibers or carbon nanotubes.

Although the present invention is described above with reference to the accompanying drawings, it is not limited thereto, but on the contrary, any useful modification could be applied by a person skilled in the art, without going beyond the ambit of the present invention, as defined by the accompanying claims. 

1-8. (canceled)
 9. A fluid dispenser member comprising a body and manually-actuated dispenser means that are movable in said body between a rest position and a dispensing position, said dispenser means being urged resiliently towards their rest position by a resilient member, said resilient member comprising a plurality of spring cells that are arranged in parallel around a longitudinal axis of said resilient member, forming a spring stage, and said resilient member includes a plurality of spring stages that are superposed along said longitudinal axis, said dispenser member being characterized in that a spring stage comprises a top undulating ring having multiple undulations, and a bottom undulating ring having multiple undulations, said top and bottom undulations being arranged relative to each other in such a manner that said top and bottom undulating rings are in contact at a plurality of contact points distributed around said longitudinal axis, a spring cell being defined between two adjacent contact points of said spring stage, said resilient member being made by injection molding a synthetic material, such as POM, the top and bottom axial ends of said resilient member being formed by flat rings.
 10. A member according to claim 9, wherein the top undulating ring of a spring stage forms the bottom undulating ring of the spring stage arranged directly above, and the bottom undulating ring of said spring stage forms the top undulating ring of the spring stage arranged directly below.
 11. A member according to claim 10, wherein the contact points of a spring stage are offset relative to the contact points of the spring stages that are directly above and directly below, a contact point of the spring stage being arranged half way between two contact points of the spring stage that is directly above, and half way between two contact points of the spring stage that is directly below, so that the resilient deformation forces of each cell are distributed in approximately uniform manner over all of said cell.
 12. A member according to claim 9, wherein said synthetic material is filled with materials that increase resilience and/or prevent creep, such as glass fibers and/or carbon nanotubes.
 13. A member according to claim 9, wherein said fluid is a liquid or powder medication.
 14. A member according to claim 9, wherein said dispenser member is a pump or a valve, said dispenser means being the pump piston or the valve member, and said resilient member forming the return spring of said pump or valve.
 15. A member according to claim 9, wherein said dispenser member is a compressed-air expeller, said dispenser means being the piston of the air expeller, and said resilient member forming the return spring of said air expeller.
 16. A fluid dispenser device comprising a reservoir containing said fluid, said device being characterized in that it further comprises a dispenser member according to claim
 9. 